In an ideal world, all our Internet browsing would be encrypted to prevent snooping and hijacking. But the world isn't ideal as yet so Mozilla's latest Firefox build has a new feature: opportunistic encryption.
A bit more safety is better than none
While the feature sounds dodgy, in reality it is merely a means of adding another layer of security by adding encryption without needing to pass on credentials from one endpoint to another. Usually secured, encrypted sites rely on digital certificates for encryption. Opportunistic encryption does not rely on authentication and needs much less server setup for it to work, in comparison with the tweaks needed for servers to support HTTPS.
Why is this a big deal? On sites that publish most or all of their content in ordinary, unsecured HTTP, this leaves the sites wide open to people who can manipulate the content. This compromises the content's integrity as well as puts website visitors or users at risk.